Circular saw blanks and, especially, hot-sawing circular saw blanks generally are relatively large and thick and are obtained from stock following a rolling process which produces ridges, corrugations or other irregularities. These must be straightened or removed by dressing. A typical dressing process is the peening of the blank with a hammer or the like.
The circular saws which are fabricated according to the present invention are industrial circular saws, e.g. hot-sawing circular saws of the type used in metallurgical plants, rolling knolls and the like for the cutting of rolled or extruded profiles, blooms ingots, billets or blocks, and other metallurgical intermediate products.
A circular saw blank for use in the hot sawing of metallurgical products generally is constituted as a heavy sheet-metal body having a diameter of up to 2000 mm. and a thickness of up to 20 mm. or more.
Since the blank is cut from rolled sheet metal, it is obtained from the rolling process with corrugations, dislocations, bends and other irregularities which must be straightened or dressed by a straightening or dressing process.
This is important because rotary or industrial circular saws are driven at angular velocities of 2000rpm or more. Thus any irregularities, even if minor, which can result in lateral distortion of the blade can endanger operating personnel and/or lead to failure of the saw.
The dressing or straightening process has been effected hereto with the aid of mechanical hammers which are hand-held or are provided in a support frame with a stationary anvil. When a hand-held hammer is employed, it must be displaced relative to the sheet-metal circular saw blank while, when the hammer is juxtaposed in a frame with a fixed anvil, the circular saw blade must be manually displaced from two or more sides by operating personnel so that all of the irregular surfaces are ultimately shifted beneath the fixed working point of the device.
The process is thus labor-intensive and relatively expensive and practice has shown that it often is not sufficiently precise.
In fact, only when operating personnnel by hand carefully position each portion of the blank at the working location is there any significant improvement in the precision of the straightening operation. Naturally, such care by the operating personnel in holding, moving and locating the blank, increases the cost of the product markedly.